POS0010 THE PSORIATIC ARTHRITIS 5-THERMOMETER SCALES (PsA-5Ts): A NEW INSTRUMENT FOR ASSESSING THE STATUS OF DISEASE ACTIVITY IN PSORIATIC ARTHRITIS
Authors: F. Salaffi, M. Carotti, S. Farah, M. Di Carlo
Journal: Annals of the Rheumatic Diseases (2022)

Background There are a variety of composite disease activity monitoring methods and patient-centered metrics available for psoriatic arthritis (PsA). The Psoriatic Arthritis 5-Thermometer scales (PsA-5Ts) is a new tool, proposed, with the aim of improving its diagnostic accuracy. Objectives The goal of this research was to evaluate data on the measurement qualities of the PsA-5Ts, a composite measure of disease activity in PsA patients, in a real-world scenario (Figure 1). Figure 1. The Psoriatic Arthritis 5 Thermometer scales (PsA-5Ts) scoring and calculation rule Methods A total of 155 PsA patients were enrolled between May 2018 and December 2021. Adult-onset PsA CASPAR criteria were used to classify patients affected by PsA, while ASAS criteria were used to classify patients affected by axial-PsA (axPsA). All patients completed the PsA-5Ts, a simple instrument with five “thermometers” that incorporate pain, fatigue, physical function, skin disorders, and depression into a single assessment of disease activity. Additional continuous measures of disease activity (e.g., DAPSA, PASDAS, CPDAI) and patient-reported outcomes (PROs) measures of disease health status (e.g., PSAID and SF-36) were analyzed as comparisons. Spearman’s correlations and cross-tabulations were used to examine concurrent validity. Receiver operating characteristic (ROC) curve method was used to assess discriminant validity. As an external criterion, the Minimal Disease Activity (MDA) levels were used. Results The 96 female and 59 male patients ranged in age from 20 to 79 years old and had been living with PsA for an average of 8.35.2 years (6 months to 22 years). The PsA-5Ts’ area under the ROC curve (AUC-ROC) was 0.944. (95 percent CI 0.895 to 0.974) (Figure 2). The PsA-5Ts had same discriminant validity as the DAPSA, CPDAI, PASDAS, and PSAID, but it was better than the SF-36 (p=0.0011). PsA-5Ts subscales were highly significantly different between the MDA status (all at p&lt;0.0001) when categorizing patients into those who rated their condition as reaching MDA (Kruskal-Wallis test). PsA-5Ts were also shown to have a remarkable (p&lt;0.0001) correlation with known PsA activity measurement techniques. Figure 2. ROC curve analysis (AUC-ROC curves values, standard error and 95% confidence intervals) for the discriminatory power of disease activity, according to the different composite disease activity indices (DAPSA; CPDAI and PASDAS) and patient-reported outcomes (PROs) measures (PsA-5Ts, PSAID and SF-36). Receiver operating characteristic curves illustrating the relationship between sensitivity and complement of specificity (100-specificity) in PsA for activity measures using MDA as an external indicator. A line that runs diagonally across the figure from lower left to upper right will have an area of 0.5; this represents an instrument that does not discriminate. Conclusion For the evaluation of disease activity in PsA, PsA-5Ts is a useful alternative to continuous composite indices and other patient-centered assessments. The PsA-5Ts make data collection simpler, and they should be used in both clinical studies and everyday clinical treatment. In order to establish the tool’s clinical relevance, longitudinal construct validity, which concerns the measure’s capacity to identify a real change in health status as well as its accuracy in detecting changes of various magnitudes, must be addressed. References [1]Salaffi F, Di Carlo M, Carotti M, Farah S. The Patient-Reported Outcomes Thermometer-5-Item Scale (5T-PROs): Validation of a New Tool for the Quick Assessment of Overall Health Status in Painful Rheumatic Diseases. Pain Res Manag. [2]Di Carlo M, Becciolini A, Lato V, Crotti C, Favalli EG, Salaffi F. The 12-item Psoriatic Arthritis Impact of Disease Questionnaire: Construct Validity, Reliability, and Interpretability in a Clinical Setting. J Rheumatol. 2017;44(3):279-285. [3]Salaffi F, Sarzi-Puttini P, Atzeni F. How to measure chronic pain: new concepts. Best Pract Res Clin Rheumatol. 2015;29(1):164-186. Disclosure of Interests None declared